This invention relates to the detection of fault occurrences in electrical or power distribution systems; and, more particularly, to a detector which first detects waveform transients which may be indicative of a fault occurring somewhere in the system, and then classifies the result of the detection as a likely fault occurrence or some other type of anomaly which is likely not a fault.
In an electrical distribution system, energy in the form of a 60 Hz waveform (50 Hz in some locales) is transmitted over the power lines of the system. These waveforms exhibit a wide variety of transient conditions which are continuously occurring. Many of these transients result from such routine things as a power switch being closed or opened to turn a piece of equipment “on” or “off”, or when the operating speed of a motor is changed. The characteristics of such transients, their duration, peaks, rise and fall times, degradation rate, etc., are generally known.
When a fault occurs somewhere in the system, a transient also results. Since faults often result in power outages, it is important for the utility to be able to timely detect their occurrence and the area over which the outage extends. The utility can then rapidly respond to correct the outage and restore service to the affected area. Otherwise, if the utility waits until a customer calls to report an outage, it means the customer has already been inconvenienced.
Fault detection schemes are known in the art. See, for example, U.S. Pat. No. 7,496,430 which is assigned to the same assignee as the present invention. The present invention, however, provides a quick and efficient method of recognizing and classifying faults so to enable a utility to timely identify outages and respond to them.